The average age of 25 girls in a class is 11.2 years and that of the remaining 15 girls is 10 years. Find the average age of all the girls in the class.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 10.75 years
Given that
The average age of 25 girls in a class is 11.2 years
The average age of the remaining 15 girls is 10 years.
According to the question
The average age of all the girls in the class = [25 * 11.2 + 15 * 10]/(25 + 15)
= [280 + 150]/40 = 430/40 =10.75 years